To provide a high-quality nitride semiconductor ensuring high emission efficiency of a light-emitting element fabricated. In the present invention, when obtaining a nitride semiconductor by sequentially stacking a one conductivity type nitride semiconductor part, a quantum well active layer structure part, and a another conductivity type nitride semiconductor part opposite the one conductivity type, the crystal is grown on a base having a nonpolar principal nitride surface, the one conductivity type nitride semiconductor part is formed by sequentially stacking a first nitride semiconductor layer and a second nitride semiconductor layer, and the second nitride semiconductor layer has a thickness of 400 nm to 20 μm and has a nonpolar outermost surface. By virtue of selecting the above-described base for crystal growth, an electron and a hole, which are contributing to light emission, can be prevented from spatial separation based on the QCSE effect and efficient radiation is realized. Also, by setting the thickness of the second nitride semiconductor layer to an appropriate range, the nitride semiconductor surface can avoid having extremely severe unevenness.